For a premium synthetic layering piece, we like Patagonia's Capilene Thermal Hoodie. The Power Grid fleece traps pockets of warm air against the body for lightweight insulation while also opening air channels to improve breathability and reduce the fabric mass for lighter wear. Polartec's hydrophilic surface also absorbs sweat and moisture vapor and transfers it outside, regulating our body's microclimate for better comfort when we're burning calories in the cold. With a regular fit, the Capilene Thermal Hoodie fits perfectly over a tech tee as an outer layer or mid-layer in our cool and cold weather layering systems.